This German midget submarine named Seehund (Eng: Seal) was the most successful mini-submarine of the German Navy (Kriegsmarine). Unlike other midget submarine versions such as the Molch and the Biber which were rushed into service, the Seehund was build from scratch with all lessons learned and ready for action in late 1944.
Seehund technical features
The U-Boot, designated as type 127 or XXVII B5, was built by Fisher and Grim and had excellent technical features. The midget sub was almost 12 meters long, had a beam of 1,7 meters and a diameter of 1,3 meters. The big difference with its predecessors was that it took two operators on board, a pilot seated in front of the navigator.
The Seehund had a maximum range of 555 kilometers with a speed of 13 km/h surfaced and 115 kilometers on a speed of 5,5 km/h submerged. When an external fuel tank was added, the maximum range of the Seehund was extended to 925 kilometers. It’s safe diving depth was 30 meters with a depth record of 70 meters.
The diesel engine, made by Bussing, delivered 60 hp and the AEG electro motor gave 25 hp. When the diesel engine was converted to a closed – cycle propulsion it produced 100hp and enhanced the speed up to 15 km/h surfaced and almost 20 km/h submerged. The Seehund 227 as this type was designated was faster underwater with this power plant than the earlier 127 type.
Armament
Like the Biber it carried two torpedo’s of the G7e type on its lower side. It could attack even in though weather with 4 Beufort but hat to lay stationary when attacking submerged.
Production of the Seehund
The plan was to build a thousand of the Seehund Klein U-Boot, as the Germans called their midget submarine class. Construction of the mini-submarines started in 1944 and in September 1944 the first Seehund U-Boats were delivered. Most of these were constructed by the Schichau and G.W. Howaldt shipyards, with a handfull constructed in other factories. In total 285 Seehund midget submarines would be built before the end of the war. The last Seehund came from the production line in April 1945.
The Seehund submarine in battle
Because of his small size the Seehund was hard to detect. It did not show up on the Allied radar. It could withstand depth charges, due to its small size it was pushed out of the way and tossed around instead of being destroyed. Although it could malfunction after a depth charge assault, as the sealed off carbon dioxide compartment could tear open and poison the pilot and navigator.
Converted it could lay mines as well. In 1945 the Seehund sailed 142 sorties, sinking 8 ships and damaging another 3 ships during this period with a loss of 35 vessels. Most of these 35 Seehund U-boats sank due to technical failure, so it’s reliability was questionable.
Surviving Seehund U-boats
There are quite a few surviving Seehund U-boats. This Seehund is displayed at the Deutsches Schiffahrtsmuseum in Bremerhafen. Not all of them are in this good shape though.
Note that one of the captions is wrong: “The G7e Torpedo at the Hook of Holland Nordmole Flak Batterie in the Atlantic Wall”. The torpedo in the photo is a british Mk VIII.
Absolutely amazing, German engineering never ceases to amaze me. If the Germans had won WW2 we would probably have colonies on all the planets by now.
Its save diving depth should read Its safe diving depth
but hat to lay stationary should read but had to lay stationary
sealed off coal dioxide compartment – looks strange, should it be carbon dioxide?